K3HVG ) writes:
Don, The manual can be found on the BAMA website. I have overhauled
two HQ-120's and found that, on both, 100% of the capacitors had to be
replaced, along with a few resistors. I have to say that after the
re-capping, they now function extremely well. The HQ-120 was used by
the Navy as the RBG-2 and, generally, had a large metal tag or screened
label with the Navy nomenclature on it. The Navy version also had some
ruggedized transformers in them. I'll also add that the HQ-120, and
most other equipment from this era, like to be run on 110v. At 120v or
higher, they can run very hot and cause stress. I use a 15A Variac on my
"vintage line voltage bus" to keep things cool and calm.
Good luck with your project.
de Jeep/K3HVG

But he's talking about a National NC-120, not a Hammarlund HQ-120. Maybe
he's mixed up about the receiver he has, but that seems a stretge.

Michael VE2BVW

Don wrote:
I am restoring a National NC-120 receiver. I understand this type was
used by the US Navy during World War 2. I need a repair manual with
test information such as tube socket voltages and a schematic with
component values. One similar to the ones I have for my BC-348 R and
Bendix RA-1B that has pictorial drawings of component placement and
arrangement of wiring would be great. Also any advice from anyone with
experience with this model will be appreciated. So far I have found the
power supply voltage to be about 220 DC and all the tubes test OK, but
some of the socket voltages seem wrong to me but I am not a radio tech.
The radio was working and just faded out.

Thanks
Don VE1DLT